The field of the invention pertains to diving docks and rafts typically anchored in inland lakes and streams for sunbathing, swimming, diving and other water activities.
Unfortunately pigeons, seagulls, ducks, geese and herons find rafts pleasant resting places. As a result the bird droppings are not only unsightly and unpleasant to see and smell, but can be a health hazard and must be removed before the raft can again be enjoyed.
A wide variety of devices have been employed to humanely discourage birds from perching on rafts. Fake carvings of owls, hawks and other natural enemies have been mounted on rafts. Noise makers activated by wave motions have also been employed. However, the birds soon learn to ignore these distractions.
U.S. Pat. No. 4,748,778 discloses a wire guard assembly for piling tops to prevent seagulls, pelicans and other birds from perching thereon. U.S. Pat. No. 4,100,706 discloses a covering grid spaced above the ground to adversely condition waterfowl from roosting adjacent airports. The grid is generally rectangular and so spaced to interfere with the alighting of birds either on the ground below or on the grid itself.
A buoyant net is disclosed in U.S. Pat. No. 3,128,478 as a safety cover for swimming pools. Nets are also disclosed as cargo or person supporting components of rafts in U.S. Pat. Nos. 226,264; 901,732 and 5,013,270. Also related to the invention described below are the central supports in the form of large balls used to support pool or hot tub covers as disclosed in U.S. Pat. Nos. 3,355,745 and 4,847.925.